Internal-combustion engine



Dec. 27, 1927.

' L. SAIVES 'INTERNAL coMBsTIoN ENGINE Filed Aug. 24, 1925 2 Sheets-S1162?I 1 L. SAIVES INTERNAL GOMBUSTION ENGINE,

Dec. 27, 1927.

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sion in t e main chamber must however be' Patented 27, 1927.

UNITED STATES PATENT OFFICE- man salvas, or mecum', Imca' Assrsnoa To nous mam, or

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mEBNAL-COMBUASCEION ENGINE.

Application led lAugust 24, 1925, Serial No. 51,955, and in France October 18, 1924.

The invention relates to rovements in internal combustion engines o both the two stroke cycle and four stroke cycle type 1n which a heavy liquid fuel is vaporized, sprayed and ignited by a previously ignited mixture containing a light fuel.

The slightly volatile or heavy liquid fuel is injected either during the compression period, or at the upper dead point, at the moment of maximum compression, as is done in the case of Diesel or semi-Diesel engines, but the ignition of the charge of fuel is helped by the explosion of a mixture of more volatile or lighter fuel in an auxiliary chamber separate from the main chamber,

and communicating with it only at the mo-' ment yof the explosion of the auxiliary mix- One of the features of the invention is the fact that the compression in the auxiliary chamber is limited to that which is compatible with' efficient ignition of the mixture of volatile fuel, whilst in the main chamber, which is supplied with the heavy fuel,-the compression may be carried to a high degree as in the well known Diesel engines, making it possible to burn heavy fuels of all kinds The degree of compresless than the pressure produced by the explosion of the mixture inthe auxiliary chamber. An apparatus has further been provided which makes the. starting-up of suchan engine as easy as that of an engine on a self-propelled vehicle by lowering the degree of compression in the main chamber during the starting-up period. It will thus be veasier to ensure starting, running unloaded and even on light loads by means of the volatile light fuel alone.

The heavy fuel may be injected `onto the main chamber, or alternatively introduced above the communicationuvalve between the two chambers so as to be injected into the main chamber at the moment of explosion.

In the accompanying drawings Figs. 1, 2 and 3 show a construction for carrying out the invention in a four-stroke cycle engine,

` whilst Figs. 4 and 5 show a construction in the' case of a two-stroke cycle engine.

Referring to Figs. 1 and 2 it will be seen that the engine comprises a combustion vchamber at high compression. An ignition chamber 2 at low compression communicates on the one hand with the chamber 1 by an other ignition device.

The heavy fuel is introduced either into vthe chamber -1,.Fig. 1, by theinjector 10 in the form of spray during the period of compression, or at the upper dead-point according to the regulation, or alternatively into the ignition chamber 2, Fig. 3, at 10 through a nozzle 12 and a passage above the automatic valve 3.

The injector 10 is connected to an ordi- Ynary volumetric pump forcing in the heavy fuel at the desired-moment.

The nozzle 12 may also be connected to a volumetricpump bringing the fuel to 11 or again it may be connected to a container, the fuel bein supplied at .11 automatically owing to t e decrease of pressure caused in the chamber 2 by the down stroke of the working piston., In this latter case the admission of the heavy fuel at 11 takes place at the same time as the suction of the mixture of lighter fuel into the chamber 2.

The oint 5 of air intake into the cylinder 13 is c osen in such manner as to introduce into the chamber 2 through the passa e 4' pure air compressed to a low pressure al owllilglof the ignition of the mixture of lighter 'the valve 6. At the bottom dead point t e chamber 2 is filled with inflammable mixture and the cylinder 13 with pure air.

At the second stroke of the cycle the piston 14 moves upwards, which corresponds to the compression eriod in the chambers 1 and 2. The cham r 2 is cut oif at the point 5 from the ignition chamber, whence there results a reduced compression required for' [the iniiammable mixture contained therein.

The piston 14 continuing its up stroke compesses the air to a high degree in the chamr 1 only. During the up stroke of the piston the heavy fuel is introduced by the injector 10 at the moment desired for obtainmg a ood spraying.

At t e third stroke 4of the cycle and a little before the upper dead point is reached the i tion devlee 9 comes into operation, igmtes the charge contained in the chamber 2, causing an increase of pressure higher than the compression of the mixture of air and heavy fuel in the chamber 1. The valve 3 o the gases produced by the the exp osion of the mixture in the chamber 2 pass into the chamber 1 and ignite the mixture of heavy fuel and air which then burns. Expansion occurs and the beginning ofthe exhaust takes place towards the bottom dead int.

At the fourth stroke of the cycle under the action of the piston which moves up again the gases produced by the combustion are expelled.

Fig. 3 shows a construction in which the operation is identical with the above, save that the heavy fuel is introduced in an unatomized state the nozzle 12 and passage above the valve 3.

The explosion of the charge in the chamber 2 opens the valve 3 and forces the heavy fuel into the chamber 1 at the same time vaporizing it and assisting its ignition.

The starting up of such an engine 4,may be effected by an auxiliary engine, by compreed air or other suitable means. It can also be done by hand like the 'engines of self-propelled vehicles.

In order to start by hand which can be done easily with the reduced compressions, it is necessary to maintain in the chamber 1 a ressure equal to that limited inthe cham er 2 bythe closing of the passage 4 by the piston 14 at the point 5.

A device consisting ofY a decompression cam acting upon the exhaust valve permits the maintenance in the chamber 1 of the same pressure as that obtaining in the chamber 2, when the piston reaches the polnt 5. This device is similar to that employed in explosion engines to aid starting up.

For starting up the engine is not S11 plied with' heavy fuel, but it starts on the light inflammable 'mixture.- 0nce started.

the distribution becomes normal, and the above described device for decompression` is suppressed, high compression is obtainedA in the'chamber 1 and the heavy fuel maybe supplied at 10 or at 11.

VLacasse It is obvious that the engine may be supplied with the explosive mixture in 2 when rumiing unloaded and even on light loads.

When the engine is sufficiently warmed up the operation of the ignition chamber 2 may be stopped, the engine then working like an engine with ordinary injection, the ignition ofthe heavy fuel being obtained at this moment by the temperature of the high compression in the chamber l.

As the valve 3 cuts off communication between the chambers l and 2, this` latter is completely isolated, and the sparking plug 9 and the Valve 8 are protected from the high temperatures of combustion in the chamber 1. In the case where the engine works on heavy fuel alone it will be possible after starting up to isolate the two chambers more completely by operating a stop valve located in the passage 4, not shown in the drawing.

Referring to Figs. 4 and 5 showing the application of the improved method to a two-stroke cycle engine, it is seen that the valves 6 and 7 are omitted, their functions being replaced by the scavenging and exhaust openings 15 and 16.

e working in the chamber 2 is the same as in the case of a four-stroke cycle engine, the diierence of compressions in the chambers 1 and 2 bein obtained in the same manner aswell as 51e supplies of light and heavy fuels.

The pressure in the cylinder being alwge higher than the atmospheric pressure, e valve 8 cannot open automatically. If this valve were controlled it would be necessary to introduce the gas coming 1rom the carburetor under pressure. In order to facilitate such introduction it will suice to place the carburetor supplying the light fuel under the pressure of the scavenging air. The carburetor is placed in an impervious box 17, connected by a pi 18 with the scavenging conduit 19, the a 'ssion of petrol is through the pipe 2O coming from a container placed under suicient load, or subjected to a pressure higher than that of the scavenging air by any suitable means.

The starting up will place in the same way as in four-stroke cycle engines, a controlled discharge valve being provided on the chamber l to limit momentarily the ressure in the chamber 1 to that in the cham r 2.

It is to be understood that the communication valve between the auxiliar chamber and the combustion chamber, whic is shown as `an automatic` valve, might equally well be controlled.

Claims:

1. In an internal combustion engine having a main combustion chamber, an auxiliary combustion chamber, a communicating valve between the auxiliary and the' main combustion chamber, fuel admission means Lacasse iary 'combustion chamber, aeommunicatingv lvalve between the auxiliary and the main combustion chamber, fuel admission means for the auxiliary combustion chamber, and an air duct leading from the main chamber to the auxiliary chamber, the point of admission of air from the main chamber being at a predetermined distance below the end ofthe piston when at upper dead center.

3. In an internal combustion engine having a main combustion chamber, an auxila ary combustion chamber, a communicating valve between the auxiliary and the main combustion chamber, means for admitting high volatile fuel to the auxiliary combustion chamber, means for'admitt' low volatile fuel to the auxiliary combustlon chamber, and piston controlled means for admitting air from the cylinder tothe auxiliary combustion chamber at a lower pressure than the normal compreion pressure.

4. In an internal combustion engine hav-` ing a main combustion -ehamber, an auxiliary combustion chamber, a communicating valve between the auxiliary and the main combustion chamber, said auxiliary combustion chamber being shaped to form a fuel receptacle in conjunction with said valve, means. for admitting high volatile fuel to the auxiliary combustion chamber, means for admitt' low volatile fuel to the rece tacle, an

'ttin air from the cylinder to the auxiliary com ustion chamber at a lower pressure than the normal compression pressure.

In testimony whereof I affix my signature.

` LON SAIVES.

piston controlled means forl 

